Oral cancer is one of the most common neoplasms, and is the culmination of the chronic disease process, carcinogenesis, after long- term exposure to some carcinogenic insults such as tobacco. Its multistep and accumulative features strongly support the rationale for prevention before invasive lesions can grow. Chemoprevention is a very promising new strategy but current strategies are very far from be satisfactory because of their significant toxicity. Anti-angiogenesis has been known as one of cornerstones for the chemoprevention. Our previous studies have indicated the effectiveness for tumor therapy of selective microvascular targeting with a 585 nn pulsed dye laser (PDL), with no damage to any neighboring tissue. The goal of this proposed study is to determine whether a PDL can catalyze the effectiveness of Retinoic Acid (RA) in cancer chemoprevention of oral dysplasia. The long-term objective of this proposal is to develop a novel treatment paradigm: laser assisted cancer chemoprevention. Using cheek pouch of a hamster model, our specific aims are to determine 1) optimal laser parameters for such selective targeting, and 2) whether PDL, when used in combination with RA, can improve the efficacy and reduce toxicity of RA by itself. To our knowledge this is the first study combining laser microvascular targeting technique with a chemopreventive agent. This proposed strategy, if successful, is very likely to lead to an alternative with higher efficacy and less toxicity than current treatment methods.